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Guide

A1C chart: A1C to estimated average glucose

The A1C test shows your average blood sugar over the past two to three months as a percentage. This chart translates it into the glucose numbers you see on a meter, using the formula from the ADAG study.

A1C to eAG conversion chart

eAG = 28.7 × A1C − 46.7 mg/dL; mmol/L = mg/dL ÷ 18.016; IFCC mmol/mol = (A1C − 2.15) × 10.929. Values rounded.
A1C (%)A1C (mmol/mol)eAG (mg/dL)eAG (mmol/L)
5.031975.4
5.5371116.2
6.0421267.0
6.5481407.8
7.0531548.6
7.5581699.4
8.06418310.2
8.56919710.9
9.07521211.7
9.58022612.5
10.08624013.3
10.59125514.1
11.09726914.9
11.510228315.7
12.010829816.5

What the A1C ranges mean

The American Diabetes Association uses these A1C ranges for diagnosis:

  • Below 5.7%: normal
  • 5.7% to 6.4%: prediabetes
  • 6.5% or higher: diabetes

Treatment targets for people who already have diabetes are set individually by their doctor. A single number from this chart is not a diagnosis.

How the conversion works

The A1C-Derived Average Glucose (ADAG) study measured A1C and continuous glucose in hundreds of people and found a linear relation between them:

eAG (mg/dL) = 28.7 × A1C (%) − 46.7

For example, an A1C of 7% gives 28.7 × 7 − 46.7 ≈ 154 mg/dL. To get mmol/L, divide the mg/dL value by 18.016 (154 ÷ 18.016 ≈ 8.6 mmol/L).

Many labs outside the US report A1C in mmol/mol (the IFCC unit). The master equation between the two units is IFCC = (DCCT − 2.15) × 10.929, so 7% is about 53 mmol/mol.

Why your meter average can differ

eAG is an estimate for a population. Your own meter or CGM average can be higher or lower for the same A1C, for example when you test at different times of day, or when anaemia or other conditions affect red blood cells. Talk to your doctor if the numbers don’t match.

This page is for information only and is not medical advice.

Sources